Gripping mechanism.



J. '1.1.' GoNTL GRIPPING MECHANISM.

APPLICATION FILBD AUG. 18, 190B.

Patented Apr. 18, 1911.

wAsmNa'roN o c entre sa ar erica.,

GRIPPING MECHANISM.

To all whom it may concern.'

Be it known that I, JAMES T. FELIX CONTI, a citizen of the FrenchRepublic, and resident of Paris, France, have invented certain new anduseful Improvements in Gripping Mechanism, of which the following is aspecification.

The present invention relates to gripping mechanism, and it has for itsobject among others to provide an improved mechanism which will worksilently without shock or loss of time whatever the wear may be. Thesaid mechanism embodies a wedge curved on both faces and interposedbetween a pulley mounted on the shaft to be driven and a friction rollermounted on the driving shaft, so as to turn freely on the latter, acounter-acting spring being provided for constantly holding the rollerin Contact with both such pulley and roller in order to avoid any lostmotion.

The invention is clearly illustrated in the accompanying drawings,which, with the letters of reference marked thereon, form ,a part ofthis specification, and in which- Figure 1 is a front elevation. Fig. 2is a section on the line A-A of Fig. l. Fig. 3 is a perspective view ofthe wedge. Figs. 4L to 7 are diagrams illustrating the invention and theconstruction of the curved wedge.

Like letters of reference indicate like parts throughout the differentviews.

As shown in Figs. 1 and 2, the present gripping mechanism consistsessentially of a pulley a fixed ona shaft o and provided on itsperiphery with a flange c. On the shaft b is loosely mounted a drivinglever al supporting the axis e of the roller f. In the space betweensaid roller and the flange of the pulley is engaged a curved wedge gshown in Fig. 3 actuated through the lever 7L mounted to rotate freelyabout an axis z' on the lever 0l and acted upon by a spring y'. Thiscurved wedge has a cylindrical external surface g corresponding exactlywith the internal surface of the flange c of the pulley; its externalface g2 is formed with a determined particular curve so that the wedgeangle will be constantly the same, whatever may be the wear of thesurfaces in Contact. The said curved wedge is practically a straightwedge which has been so arched that it may be applied against theSpecification of Letters Patent.

Application led August 18, 1908.

Patented Apr. 18, 1911.

senai No. 449,184.

internal surfaces of the flange of the pulley. It may be obtained asfollows: A straight wedge A B C D, Fig. 4, is first constructed, havingthe development of the curved wedge to be made and offering the wedgeangles which is desired, the said wedge is then divided by tracing acertain number of ordinates; afterward ou a circle E (Fig. 5) having thesame radius as the internal circumference of the crown to be driven thelengt-h A B is carried to A B as well as the divisions between A and B.These divisions are connected in the center on each of the so tracedradii. The different corresponding ordinates carried, and the curve C Dobtained in joining these different points is the searched "curvePractically in order to be able to obtain a curvature on both faces, thefollowing mode of procedure may be followed. Referring to Fig. G, asbefore, a circle E is traced with the same radius as the circumferenceto be driven, then a length F G equal to the mean thickness of the wedgeto be obtained (pref erably this thickness will not exceed a. tenth ofthe radius) is transferred on a radius O F, and an isosceles triangle OG H is so constructed that the angle of the center O G II is equal tothe wedge angles. From the point I-I a circle is traced passing throughG. The said circle settles the internal surface curve of the wedge.

Fig. 7 shows a gripping mechanism comprising a flat surface wedge I. 'Ioobtain the wedging, the wedging angles formed of the right linesconnecting the contact point K of the roller f with the wedge I, to thecenters L and O of the said roller and of the pulley must have a welldetermined value, varying according to the coefficients of friction ofthe surfaces in contact, because if this angle is too great, no wedgingis produced and the wedge is carried along with the roller f, on thecontrary, if it is too small, this roller is released with greatdifficulty when it is no more to be used.

By my improved construction the definite special curve given to theinternal curved surface makes the wedge angle able to keep about aconstant value whatever the position of contact point of the wedge maybe and, consequently, whatever the wear of the rubbing surfaces may be.The wedge angle being constant, and the wedge being constantlymaintained in contact with the roller, and the surface to be driven, aperfect driv ing without shocks or loss of time and an instantaneousdisengagement is always obtained regardless of the wear.

The lever Z may be so disposed as to allow the application of severalrollers and of several curved wedges.

Having now particularly described the nature of the invention and inwhat manner the same is to be performed I say that what I claim is:

l. The combination with a shaft and a pulley thereon having a peripheralflange, of a driving lever mounted on said shaft, a roller mounted forfree rotation on the side of said lever adjacent said pulley, a curvedwedge interposed between said roller and flange with its external faceconcentric with the internal surface of the flange and its internal faceformed upon a determined particular curve whereby the wedge angle isconstantly the same notwithstanding the wear of the contacting surfacesand a lever mounted to rotate freely about an axis on said driving leverfor actuating said wedge.

2. The comb-ination with a shaft and a pulley thereon having aperipheral flange, of a driving lever mounted on said shaft, a rollermounted for freev rotation on the side of said lever adjacent saidpulley, a curved wedge interposed between said roller and fiange withits external face concentric with the internal surface of the flange andits internal face formed upon a determined particular curve whereby thewedge angle is constantly the same notwithstanding the wear ofthecontacting surfaces, a lever pivotally mounted on the first-named leverand acting on said wedge, and means carried by the firstnamed leveradjustable therethrough with its inner end acting on the tail of thesecond lever.

ln testimony whereof I aflix my signature.

JAMES TIBURCE FELIX CONTI. In the presence of- H. C. Coxn, GEORGEPico'r.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

i Washington, D. C.

